For many products, their coloring plays an essential role in terms of the customer's buying interest. In many applications for applying color to objects, the desire is that the item should be adapted to its environment in terms of its color as seen from outside it. This can be described as a “chameleon effect”.
In electrochemical coloring systems, the color can be altered by doping of the coloring agent. In doing this, it is normal to use an electrochemical cell structure. The doping of the electrochemical coloring agent is effected by the application of an external voltage. The layer structure of an electrochemical cell consists typically of an electrode, the electrochemical coloring agent, the electrolyte and a counter electrode. There must be a seal between the two electrodes in order to avoid loss of the electrolyte. If a voltage is applied between the two electrodes, then the ions in the electrolyte start to diffuse into the coloring agent, and to oxidize or reduce it, which corresponds to a p-doping or an n-doping respectively. This will depend on the nature of the coloring agent and the voltage applied.
Until now, no solutions have been disclosed which permit a variable and at the same time predefinable surface color on objects.